I just got my 18watt sox lamp setup and it seems to be working fine but there is some blackening around the base of the bulb and I wanted to make sure that was normal. I didn't notice that on my 35watt lamp so I wanted to double check.

I resized the images. they were a little too big

It's hard to tell, it could just be the way the lamp is. What ballast are you using for the 18W..?

I would also suggest you post images of the lamps (both unlit and lit) in the gallery, they are probably more likely to get seen there, not everyone uses the forum.

If you need any help with that, please ask.

Is it a new lamp?, looking at where the sodium is, it looks like the lamps been cap down when it’s been hot?
The other ‘black’ bit is just a getter added when their made.

It is a new lamp. It only been base up when its hot. I only ran it once for about 5 hours.

The "stain" along the tube length looks like just the lump of Na pooling there. It is a small lamp ans maybe the liquid Na got smeared along the tube,maybe due to some mechanical shock. I would guess it will gradually pool back...